This invention relates to a process for the manufacture of a single wetting-dispersing agent for use in the manufacture of wettable powder formulations. More particularly, this invention relates to a process of making an improved combination wetting-dispersing agent for use in the formulations of insecticides, herbicides and fungicides.
For many years, manufacturers of pesticide toxicants have incorporated surfactants into formulations to make the active ingredient readily dispersable and wettable. Development of satisfactory surfactants has encountered various undesirable characteristics relating to suspendibility, aging, ease of formulation and foaming. The development of satisfactory surfactants is further hampered by the competitive nature of the industry, thereby causing the formulator to cut costs to a bare minimum. This means the use of the largest amount of diluent possible and the cheapest surfactants possible.
Until this invention, manufacturers of pesticide formulations were forced to separately mix into the wettable powder formulation both the wetting agent and the dispersing agent. Heretofore such conventional mixing means as a ball mill, a hammer mill, ribbon blender or the like, were necessarily used because of deficiencies in either the wetting agent or the dispersing agent or both, due to such adverse properties as physical form.
As noted above, it is well known to add separately a wetting agent and a dispersing agent to pesticide formulations. Examples of this practice are described in U.S. Pat. Nos. 2,893,912 and 3,342,581. The advantages of the instant invention over these patents lies in the ability of the manufacturer of pesticide formulations to utilize a substantially smaller total quantity of surfactant due to the synergistic effect obtained upon drying. The provision of a single surfactant for pesticide formulations replaces the need for separate wetters and dispersants, reduces inventory and storage problems, decreases the possiblity of error in preparing formulations and reduces the need for mixing and handling.
It is a general object of this invention to provide a surfactant for use in pesticide formulations which combines both wetting and dispersing functions in a single powdered product. It is another object of this invention to provide a process for making a single surfactant by drying together a wetting agent and a dispersing agent. It is a further object of this invention to provide a single wetting-dispersing agent which easily combines in a pesticide formulation by simple dry blending. It is still a further object of this invention to provide pesticide formulations having a single wetting-dispersing agent combined therein and characterized by outstanding suspendibility and aging properties. Other objects will be evident from the following disclosure.